In this article Shelly Loewen outlines the power of the playground in terms of learning.
"The playground is truly a microcosm of the human learning process. With further exploration, a learning theory began to take form: We (people) learn similarly to the way we play and our learning process is a dynamic combination of our character (cognitive & affective) and sensory (psychomotor) learning style values."
http://newhorizons.org/strategies/styles/loewen.htm